2000 Bounder D.P. 39 Z house battery connections help

John, you probably know this, but try checking voltages at the batteries, then fro + to ground. If all is good then start checking from the +s to ground until you find a problem. Have you started the engine? Sometimes starting the engine will cause a hung disconnect solenoid to latch in. Contact Fleetwood.com and they may be able to send you the electrical wiring, both 120 volt and 12 volt, for the house. If you can get the plumbing prints also.
Good luck